In order to investigate the effect of Dohongsamultang and Dansameum upon restrain of thorombus formation through the experimental study, following conclusion has been obtained; 1. The number of plateletes was increased in the trial group compared with the control group, revealed significance in both of trial groups. 2. Fibrinogen was increased in trial group compared with control group, but the significance was revealed only in Sample I group of Dohongsamultang. 3. Prothrombin time was shortened in both of trial groups, but the significance was revealed in Sample I group of Dohongsa-multang. 4. FDP was decreased in both of trial groups, but the significance was revealed in Sample I group of Dohongsamultang.